Rail Device for a Firearm

ABSTRACT

The present invention improves leveling of accessories mounted on a rail on a firearm. The improved rail includes a level housing configured at a proximal end of a Picatinny Rail. The level housing compress a generally rectilinear body having a viewing window configured on a front edge of the body. The body defines a volume adapted to receive a spirit level. The volume further includes a back wall arranged at substantially about 45-degrees incident to a viewing plane. 
     The housing further includes an undersized opening on a first sidewall, which is configured to restrict the level from escaping the volume. A second sidewall arranged substantially parallel to the first sidewall includes an oversized opening further configured to slideably receive the spirit level, which is retained in place by a lock-ring.

PRIORITY CLAIM

The present application is based on, and claims priority to for allpurposes, co-pending provisional patent application No. 61/948,751 filedon 6 Mar. 2014 having the common inventor named above.

FIELD OF THE INVENTION

This invention relates generally to hand-held firearms, and particularlyconcerns both devices and methods for precisely aligning the verticalcross hair of the reticle system of an attached sighting scope to beparallel to a symmetry axis of the firearm that is vertical andperpendicular to the firearm bore.

BACKGROUND

Sighting scopes, both those that magnify the sight field and those thatincorporate reticles (but do not magnify the sight field), aretraditionally mounted on their respective rifle, pistol, or shotgun(collectively “firearm”) by means of cooperating mounting rings attachedto the receiver of the firearm. The sighting scopes include reticles,which are a system of lines, dots, cross hairs, wires, or electricallyprojected images that aid in the sighting of a target and properpositioning the firearm relative to a target. A common reticle system iscomprised of intersecting cross hairs consisting of a vertical andhorizontal cross hair.

Often, when a scope is mounted to the firearm using the scope-mountingrings attached to the firearm's receiver, the scope is mountedoff-center relative to the true axis defined by the bore of the barreland is therefore canted or rotated to some degree resulting inmisalignment of the cross hair on the scope relative to the symmetryaxis of the firearm that is vertical and perpendicular to the firearmbore.

Shooters, especially competition target shooters, tend to compensate forthe included cross hair canting by counter-rotating the firearm and thuscompromise the accuracy of this shot.

Accordingly, it is very important that the scope's cross hair alignmentsystem be in precise alignment with the corresponding axis of thefirearm, which will result in a more accurate and more repeatable shot.Further, such a system should be easy to use, visible in low light andbright light conditions, be economical to produce, robust and hardy indesign, and simple to mount to the weapon.

SUMMARY OF THE INVENTION

The present invention incorporates a conventional tactical rail, alsoknown as a Picatinny Rail (MIL-STD-913), and adapts it to furtherinclude a unique bubble-level (float level).

The present invention adapts a conventional Picatinny rail. First, asthose skilled in the art will appreciate, a Picatinny rail includes acurved or flat underside, configured to contour to common rifle barrelsand or receivers. And the top surface includes a plurality of parallelridges, the series of ridges further include either a “V”-shaped or a“T”-shaped cross-section interspersed with flat “spacing slots.”Accessories are mounted either by sliding them on from one end or theother and fixing the accessory using the ridges and shoulders (theV-shape or T-shape profile associated with the ridge). In addition tothe Picatinny rail-optimized accessory, a Weaver mount attaching schemecan be also used. In this case the accessory (such as a scope) isclamped to the rail with bolts, thumbscrews or levers. Alternatively,accessories engage one or more of the slots formed between the ridges.

The present invention incorporates a conventional Picatinny rail, whichincludes a slot width spacing of substantially about 0.206-inches (5.23mm). The spacing of slot centers is 0.394 in (10.01 mm) and the slotdepth is 0.118 in (3.00 mm). Between each slot, a ridge stands proud andthe actual width of the ridge may vary. In addition to the featuresfound in a conventional Picatinny rail, the present invention includes,at a proximal end, a housing configured to receive a spirit-type“bubble” level. This housing is fabricated from the same, continuouspiece of raw stock aluminum block, and both the housing and conventionalPicatinny rail features (at the distal end) are machined duringfabrication.

The housing is configured to receive and encapsulate a unique spiritlevel (also called a bubble level or simply a level), which is aninstrument designed to indicate whether a surface is horizontal (level)or vertical (plumb). In this application the level is oriented todetermine horizontal leveling of the accessory attached to the rail.

The level consists of a slightly curved glass tube that is incompletelyfilled with a liquid such as a colored spirit or alcohol, leaving abubble in the tube. At slight inclinations the bubble travels away fromthe center position, which is usually marked.

Alcohols such as ethanol are often used rather than water. Alcohols havelow viscosity and surface tension, which allows the bubble to travel thetube quickly and settle accurately with minimal interference with theglass surface. Alcohols also have a much wider liquid temperature range,and won't break the vial as water could due to ice expansion. A colorantsuch as fluorescein, typically yellow or green, may be added to increasethe visibility of the bubble.

To further aid in light reflectivity of the level, the housing includesopen ends on the front and back. Further, a polished machined surfaceinclined substantially about 45-degrees relative to the viewing windowserves as a back wall behind the vial. This concentrates and reflectsmore light toward the user, making the present invention highly readableeven in low-light conditions.

The present invention would work equally well by similarly adapting aWeaver rail, NATO-standard rail, or one-piece rail mount with adove-tail, or holes with screw or other fastener mount or side clamps tohold rings. The primary difference between the Picatinny rail and aWeaver rail is the size of the slots: Weaver rails have a slot width of0.180 in (4.57 mm), but are not necessarily consistent in the spacing ofslot centers.

One contemplated embodiment of the present invention includes animproved leveling device for rifle accessories utilizing a PicatinnyRail the improved leveling device comprises a level housing configuredin a proximal end of the Picatinny Rail, the level housing comprising agenerally rectilinear body having a viewing window configured on a frontedge of the body, the body defining a volume adapted to receive a spiritlevel, the volume further including a back wall arranged atsubstantially about 45-degrees incident to a viewing plane;

The level housing further comprising an undersized opening on a firstsidewall, the undersized opening configured to restrict the spirit levelfrom escaping the volume adapted to receive the spirit level and anoversized opening on a second sidewall, the second sidewall configuredsubstantially parallel to the first sidewall and wherein the first andsecond sidewall are substantially perpendicular to the viewing window,the oversized opening further configured to slideably receive the spiritlevel; and

A lock-ring is configured to engage the oversized opening whereby thespirit level is restricted from escaping the volume.

In another contemplated embodiment, the present invention contemplates adevice for a rifle, the device comprising:

a Picatinny or Weaver rail or one-piece rail with a dovetail cross slotcomprising a plurality of mounting holes and a plurality of interspacedridges and slots, the rail having a proximal end consisting of a levelhousing;

The level housing comprising a generally rectilinear body having aviewing window configured on a front edge of the body, the body defininga volume adapted to receive a spirit level, the volume further includinga back wall arranged at substantially about 45-degrees incident to aviewing plane;

The level housing further comprising an undersized opening on a firstsidewall, the undersized opening configured to restrict the spirit levelfrom escaping the volume adapted to receive the spirit level and anoversized opening on a second sidewall, the second sidewall configuredsubstantially parallel to the first sidewall and wherein the first andsecond sidewall are substantially perpendicular to the viewing window,the oversized opening further configured to slideably receive the spiritlevel; and

A lock-ring is configured to engage the oversized opening whereby thespirit level is restricted from escaping the volume.

DRAWING

FIG. 1 is a top view of a preferred embodiment of the present invention.

FIG. 2 is a side view of the embodiment of FIG. 1.

FIG. 3 is a cross-sectional view along the line 3-3 of FIG. 1.

FIG. 4 is a cross-sectional view along the line 4-4 of FIG. 1.

FIG. 5 is an offset frontal view of the embodiment of FIG. 1.

FIG. 6 is a partial front view detailing the level housing on a modifiedPicatinny Rail according to a preferred embodiment of the presentinvention.

FIG. 7 is a partial side view of the level housing of FIG. 6.

FIG. 8 is side view of the rail device of FIG. 1 and depicts systemusing the rail device.

FIG. 9 is a cross-sectional side view of the level housing portion ofthe rail device of FIG. 1 along the line 9-9 of FIG. 6.

FIG. 10 is a representational view illustrating a preferred angle of theback wall of the level housing of FIG. 9.

DESCRIPTION OF THE INVENTION

Possible embodiments will now be described with reference to thedrawings and those skilled in the art will understand that alternativeconfigurations and combinations of components may be substituted withoutsubtracting from the invention. Also, in some figures certain componentsare omitted to more clearly illustrate the invention.

Although the present invention is discussed relative to a Picatinnyrail, those skilled in the art will appreciate that the design, spirit,and scope of the invention can readily be adapted to other mountingsystems, and this discussion, accordingly, should not be limiting. APicatinny rail is also known as a MIL-STD-1913 rail and is a bracketthat provides a standard mounting platform for accessories andattachments. Similarly, a Weaver rail mount, which uses a pair ofparallel rails and several slots perpendicular to these rails, is partlycompatible with the Picatinny rail—and accordingly, the teachings of thepresent invention are readily adaptable to a Weaver rail including olderWeaver systems that use two pieces mounted a distance apart from oneanother, typically on the receiver of a rifle over the bolt openingwhere the cartridge would be inserted and/or ejected. And, the presentinvention can be readily adapted to a NATO Accessory Rail (NAR), whichis backwards compatible with the Picatinny rail.

Some limitations of rail mounting systems that are overcome by using thepresent invention with a Picatinny rail can be overcome withoutdetracting from the spirit and scope of the present invention. Forexample, the slots on a Weaver rail system have a slot width of 0.180 in(4.57 mm), but are not necessarily consistent in the spacing of slotcenters.

The improved rail device 10 of the present invention greatly improvesover the state of the art and eliminates problems associated withconventional scope mounting. The improved rail device provides windageand elevation calibration allowing a shooter to optically center thereticle for maximum performance from a mounted riflescope S (in FIG. 8,for example). As FIG. 8 shows, in one preferred embodiment the improvedrail device 10 includes two Leupold Mark 4 rings (R1 and R2) tocompliment the rail mount. Additionally, the improved rail deviceincludes a 20 MOA forward slope, which enables the improved rail deviceto be machined and combined with a sine bar to allow for a neutral to 25MOA forward slope quickly and easily, and shims, (not shown) ifrequired, are understood to be included in this system.

FIGS. 1-10 illustrate a first preferred embodiment of the presentinvention. The present invention comprises an improved rail device 10for improved alignment of accessories mounted to a firearm, such as arifle. The improved rail device is suitably configured to enable perfectalignment for a scope or other accessory for a firearm. The improvedrail device includes a plurality of rail mounting features as would beunderstood in conventional rail mounting devices, such as a Weaver railor Picatinny rail, or NATO rail and includes a rail body 12 having aproximal end 13 and a distal end 15, the proximal end includes aleveling device. By proximal end 13, I mean that end which faces theshooter when targeting a scope mounted on a rifle, for example.

In one preferred embodiment, the present invention includes many of thefeatures of a conventional Picatinny rail. And, accordingly, the presentinvention includes a slot width spacing of substantially about0.206-inches (5.23 mm). The spacing of slot centers is 0.394 in (10.01mm) and the slot depth is 0.118 in (3.00 mm). A first plurality of slotsarranges at the proximal end of the body of the present invention, asecond plurality of slots arranges at the 13 distal end of the body ofthe present invention and an intermediate bridge portion 17 arrangesintermediate to the proximal 13 and distal 15 ends.

The leveling device includes a level-housing 30 configured at theproximal end 13 of the rail body 12. The level housing includes areflective illumination feature the produces the brightest scope levelusing ambient light. The level housing further includes a canteddirection that enable a shooter to use the level bubble from a shootingposition.

An improved rail mounting system comprises an improved rail device, oneor more self-leveling rings, and a conventional scope. The presentinvention contemplates an improved rail device comprising a rail body 12comprising a proximal end 13 and an oppositely disposed distal end 15with an intermediate bridge 17 spanning between the proximal and distalends. Each respective proximal and distal end comprising a plurality ofslots 14 and ridges 16 predictably spaced along a top surface 22 of therail body, ideally having the characteristics of a Picatinny rail,however, alternative contemplated embodiments adopt other conventionalrail arrangements including Weaver or NATO standard rails, for example.

The proximal end further comprising a level housing, the level housingcomprising a front wall 37, a bottom wall, two opposing sidewalls 34 and39, and a rounded top and a window 32 arranges whereby so that a levelbubble 50 can be viewed at many useful angles when mounted on a rifle,and a back wall comprising a highly polished surface arranged atsubstantially about 45-degrees from a vertical plane established by thefront wall of the level-housing;

As will be well appreciated by those skilled in the art, the rail 12includes a plurality of slots 14 and ridges 16 predictably spaced alongthe top surface 22 of the rail. Conventional mounting holes 18 are alsodispersed, as would be expected. Although this invention discusses aPicatinny Rail, other similar mounting aids could be readily modified toinclude the improvement of the present invention. The ridges 16, perhapsbest illustrated in FIG. 3, which is a cross section of the rail 12 atline 3-3 in FIG. 1, have a substantially flat top surface and opposingshoulders to which an accessory may be configured to attach.

Making specific reference to FIGS. 1, 2, and 5, the level-housing 30arranges on the proximal end 13 of the rail 12. The level-housing 30includes a front wall 37, a bottom wall, two opposing sidewalls 34 and39, and a rounded top. A window 32 arranges so that a level 50 can beviewed at many useful angles when mounted on a rifle.

FIGS. 5-9 further detail the level-housing 30. A first sidewall 29includes an undersized opening 38 that is sized so that a level 50cannot escape the opening. However, the opening should be sufficientlylarge to let as much ambient light into the housing's chamber. Theopposite, or second, sidewall 34 includes an oversized opening 36, whichconfigures to allow the spirit level 50 slide into the chamberencapsulated by the level housing. A retainer clip 60 configures tosecure the level 50 inside the chamber.

Importantly, the chamber includes a back wall 35 that is angledsubstantially about 45-degrees relative to a vertical plane establishedby the front wall of the level housing. This back wall should be machinepolished to be highly reflective, whereas the rest of the device 10 maybe painted a flat black or other color as dictated by its use.

With specific reference to FIGS. 6, 9, and 10, a level housing—in oneparticular preferred embodiment includes a window 32, which is shown inthe cross-sectional profile view of FIG. 9. This window enables ashooter to clearly view the spirit level bubble from shooting position(The spirit level is not depicted in FIGS. 9 and 10). The angle of thisback wall 35 is important and is substantially about 45-degrees relativeto a constructed vertical reference line and from a constructedhorizontal reference line, which will be further explained in relationto FIG. 10, below. As FIG. 9 illustrates, the back wall 35 arranges atan acute angle relative to a constructed vertical. The angle ofinclination of the back wall 35 is depicted as the constructed linemarked A-A in FIG. 9. A parallel line P1-P1 is constructed offset fromthis back wall angle inclination reference line A-A as a matter ofconvenience. A horizontal line OBA-OBA is parallel to, but offset fromthe bore axis of the firearm; this reference axis is also parallel tothe long axis of the rail device 10. A vertical line V-V isperpendicular to this offset bore axis OBA. With reference to FIG. 10,the aforementioned constructed lines are duplicated with the componentsof the level housing omitted from this view. From this the acute angleof inclination “a” is shown relative to the vertical axis V-V. In onepreferred embodiment the angle of inclination “a” (reflecting theorientation of the back wall 35) is substantially about 45-degrees:However, those skilled in the art will understand that this angle couldrange from substantially about 5-degrees to substantially about85-degrees, depending on many factors.

The two side openings 36 and 38, cooperating with the window, and highlypolished back wall 35 result in a highly visible level even in low lightconditions.

The level 50 is a conventional bubble level or spirit level that has abubble 52 and centering lines 54 and works as would be conventionallyunderstood by those skilled in the art. The level 50 is arrangedhorizontally to establish that the accessory mounted to the rail islevel.

The device 10 is machined from a block of aluminum or steel, stainlesssteel, carbon fiber, brass or other metals, alloys, or plastics, aswould be understood in this art.

One method of configuring a rifle having a receiver with the improvedrail device of the present invention includes the following steps:

Providing an improved rail device comprising a proximal end with atleast one slot and ridge and a distal end with at least one slot andridge, the proximal end further including a level housing comprising aspirit level, a viewing window configured to enable a shooter to viewthe spirit level from a shooting position, and the spirit level having aback wall that is arranged at an inclined angle substantially about45-degrees from a vertical reference line that is perpendicular to thebore axis of the firearm and wherein the rail device includes a proximalbase element and a distal base element;

Attaching the proximal base element to the proximal end of the receiver;

Attaching the distal base element to the distal end of the receiver;

Verifying that the top of the distal base element when mounted to thereceiver and the top of the proximal base element when mounted to thereceiver lie in the same horizontal plane;

If the tops of the distal base element and proximal base element are notcoplanar, shimming one of the base elements to bring both tops into acommon plane; (providing one or more shims to enable this);

Attaching the improved rail device to the respective proximal baseelement and distal respective element using screws provided including atleast one 10-32 flat head cap screw and at least one 10-32 button headscrew;

Providing one or more rings configured to selectively couple to at leastone rail on the improved rail device;

Using a vise, leveling the rifle and base in the vise and hang a plumbobo from a ceiling across the room from the rifle mounted in the vise;

Placing the scope in the ring halves, snugging the ring caps afteraligning the reticle to the string line;

Providing a collimator and inserting the collimator into the bore andaligning the collimator with the scope reticle;

Turning the windage dial (left or right) until the reticle stops movingin the collimator;

Counting the number of clicks or MOA as the windage knob is turned inthe opposite direction and taking the number of clicks or MOA anddividing by 2, thus centering the windage adjustment in the erectortube; repeat this for the elevation adjustment;

With the reticle centered in the scope, removing the scope from the railand snugging the 10-32 pivot screw on the proximal base element andsnugging the 10-32 button head screw on the distal base element;

Re-attaching the scope and reading the collimator/reticle alignment;shifting or taping the base left or right to align it with thecollimator for windage; and tightening the button head screw;

Using a transfer punch, lightly center punching the location of thefront (distal) locking screw in the distal (front) base element;removing the distal base element from the receiver and placing it in amill vise;

Locating the center punch mark and center drilling, complete drillingwith a #22 drill and tapping a 10-32 tap;

Cleaning both base elements and refinish if necessary;

Cleaning the 6-48 tapped holes in the receiver with Acetone and cleaningthe 6048 screw;

Using blue or purple grade of Loctite, applying a small drop to each ofthe base element base screws; and attaching the respective bases to thereceiver and tightening the respective bases to the receiver; and

Zeroing the rifle conventionally at a range.

Although the invention has been particularly shown and described withreference to certain embodiments, it will be understood by those skilledin the art that various changes in form and detail may be made withoutdeparting from the spirit and scope of the invention.

I claim:
 1. A rail device configured to arrange in parallel to a boreaxis of a firearm, the rail device comprising: a rail body comprising aproximal end and an oppositely disposed distal end and a bubble-levelhousing coupled to the proximal end wherein the proximal end furthercomprises at least one proximal end slot and ridge feature; the distalend further comprises at least one distal end slot and ridge feature;the rail body further comprises a bridge section intermediate to andlinking the proximal and distal ends; the proximal end further comprisesa bubble-level housing; the bubble-level housing further comprises afront wall, a bottom wall, two opposing sidewalls, a back wall and a toparranged to define an interior chamber, the interior chamber adapted toreceive a level, further the two opposing sidewall respectively furthercomprise an opening configured to allow ambient into the interiorchamber, and the back wall further configures to arrange atsubstantially an angle of inclination relative to a vertical axis, thevertical axis being defined to lie in a plane that is perpendicular tothe bore axis; and the level is disposed in the interior chamber.
 2. Therail body of claim 1 wherein: the at least one proximal end slot andridge feature comprises a Picatinny rail slot and ridge feature; and theat least one distal end slot and ridge feature comprises a Picatinnyrail slot and ridge feature.
 3. The rail body of claim 1 wherein: the atleast one proximal end slot and ridge feature comprises a Weaver railslot and ridge feature; and the at least one distal end slot and ridgefeature comprises a Weaver rail slot and ridge feature.
 4. The rail bodyof claim 1 wherein: the at least one proximal end slot and ridge featurecomprises a NATO-standard rail slot and ridge feature; and the at leastone distal end slot and ridge feature comprises a NATO-standard railslot and ridge feature.
 5. The rail body of claim 1 wherein: the angleof inclination relative to a vertical axis is substantially about45-degrees.
 6. The rail body of claim 1 wherein: the back wall furthercomprises a machined surface so to reflect ambient light through thebubble spirit level.
 7. The rail body of claim 1 wherein: the twoopposing sidewalls further comprise a first sidewall and a secondsidewall; the first sidewall comprises an undersized opening configuredto restrict the level from escaping the interior chamber; the secondsidewall arranged substantially parallel to the first sidewall andcomprises an oversized opening further configured to slideably receivethe level, which is retained in place by a lock-ring.
 8. The rail bodyof claim 1 wherein: the level is a bubble-spirit level.
 9. An improvedrail device adapted to be arranged in parallel with a bore axis of afirearm, the rail device comprising a proximal end having at least onePicatinny rail slot and ridge feature, a distal end having at least onePicatinny rail slot and ridge feature and an intermediate linking bridgesection, the improvement comprising: a bubble-level housing disposed onthe proximal end, the bubble-level housing comprising a front wall, abottom wall, two opposing sidewalls, a back wall and a top arranged todefine an interior chamber, the interior chamber adapted to receive abubble-spirit level, further the two opposing sidewalls respectivelyfurther comprise an opening configured to allow ambient into theinterior chamber, and the back wall further configures to arrange atsubstantially about a 45-degree angle of inclination relative to avertical axis, the vertical axis being defined to lie in a plane that isperpendicular to the bore axis, the back wall further comprises amachined surface so to reflect ambient light through the bubble spiritlevel; and the bubble-spirit level is disposed in the interior chamber.10. An improved Picatinny rail, the improvement comprising: a housingdisposed on a proximal end of the rail, the housing comprising a frontwall, a bottom wall, two opposing sidewalls, a back wall and a toparranged to define an interior chamber, the interior chamber adapted toreceive a level, further the two opposing sidewalls respectively furthercomprise an opening configured to allow ambient into the interiorchamber, and the back wall further configures to arrange atsubstantially about a 45-degree angle of inclination relative to avertical axis, the vertical axis being defined to lie in a plane that isperpendicular to the bore axis, the back wall further comprises amachined surface so to reflect ambient light through the interiorchamber; and the level is disposed in the interior chamber.
 11. Theimproved Picatinny rail of claim 10 wherein: the two opposing sidewallsfurther comprise a first sidewall and a second sidewall; the firstsidewall comprises an undersized opening configured to restrict thelevel from escaping the interior chamber; the second sidewall arrangedsubstantially parallel to the first sidewall and comprises an oversizedopening further configured to slideably receive the level, which isretained in place by a lock-ring.
 12. The improved Picatinny rail ofclaim 10 wherein: the level is a bubble-spirit level.